Inductive Coupling Research Articles

High Step‐Up Isolated Multi‐Input Converter Based on Three‐Winding Coupled Inductor and Quasi‐Z‐Source for Excellent Voltage Gain With Independent Control and Expandability

ABSTRACTThis article introduces a high step‐up isolated multi‐input converter (HSIMIC), which utilizes a three‐winding coupled inductor and a quasi‐Z‐source to obtain an extra‐high voltage gain and to feature galvanic isolation. The HSIMIC only requires a minimum count of active switches. In HSIMIC, diodes have zero current switching (ZCS) features at turn‐off, and leakage energy can be recycled. Based on the configuration of HSIMIC, the input sources can be processed simultaneously or individually. Even if either of the input sources is interrupted, the converter can still function and maintain the high step‐up characteristic. In addition, the input port number can be easily extended to deal with more clean energy sources. The converter operation principle, theoretical analysis, essential parameter design, and simulations are carried out. A 400‐W prototype is built and then tested to verify the theoretical analysis and validate the proposed HSIMIC.

Analysis and Design of Stacked Coupled Inductor Quadratic Boost Converter With a Lossless Snubber Cell

ABSTRACTThis paper introduces the stacked coupled inductor quadratic boost converter with an inductorless, passive lossless snubber cell suited for high step‐up applications with various microgrids. Some design constraints can be selected from the voltage gain techniques of the high step‐up converters to obtain the solution of improvement performance of converter. The proposed converter utilizes quadratic boost converter and coupled inductor to attain high voltage gain beyond the voltage multiplier/lift cells. In this proposed converter, the use of a stacked coupled inductor type introduces the leakage inductor to snubber cell as an inductor without using an extra inductor in proposed snubber cell. Thus, a regenerative snubber cell is used to achieve a high system efficiency. Compared with earlier counterparts, the solution of attaining a high voltage gain in the proposed converter and passive lossless snubber cell leads to an increase in the converter's performance, reliability, and robustness. The theoretical expectations are supported by simulations and verified by experimental results obtained by implementing a 300‐V, 120‐W prototype.

Power Transmission Technology Using Wireless Network

In this paper, we have presented the concept of wireless transmission i.e. power transmission without using any type of the electrical conductor and/or wires. We have presented an idea that is discussed here about how electrical energy can be transmitted as microwaves so that to reduce the transmission, allocation and other types of losses. Such technique is known as Microwave Power Transmission (MPT). We have also presented and correlated several aspects with the currently available Power transmission systems to the related history of wireless power transmission systems and also the related developmental changes. The basic design, merits and demerits, applications of Wireless Power Transmission are also discussed . The paper describes the various types of WPT technologies; Inductive Coupling, Magnetic Resonance and Radio Frequency (RF) technology. It also discusses the advantages and shortfalls of each type. An extensive survey of past works was discussed. Results from the research findings showed that distance and conversion efficiency were limiting factors in implementing wireless transfer technology

Synthesis and Comparison of a Family of Three-Winding Coupled Inductor High Step-Up DC–DC Converters Using Stacked, Parallel, and Cascade Association Techniques

Synthesis and Comparison of a Family of Three-Winding Coupled Inductor High Step-Up DC–DC Converters Using Stacked, Parallel, and Cascade Association Techniques

Ultrahigh Step-Up DC-DC Converter Utilizing a Three-Winding Coupled Inductor and a Switched Capacitor Network With Reduced Input Current Ripple and Low Voltage Stress on the Power Switch

Ultrahigh Step-Up DC-DC Converter Utilizing a Three-Winding Coupled Inductor and a Switched Capacitor Network With Reduced Input Current Ripple and Low Voltage Stress on the Power Switch

Passive control strategy of inductive power transfer to microimplants based on ferroelectric dielectrics

Abstract In this study, a passive control strategy of inductive power transfer (IPT) using ferroelectric multilayer ceramic chip capacitors (MLCCs) is presented. The required system parameters, i.e., ferroelectric hysteresis, frequency of the IPT, and voltage range across the MLCCs are reported. The receiver circuit consists only of a parallel resonant circuit, a halfwave rectifier and a load; the passive control of the IPT is achieved exclusively by the nonlinear properties of the ferroelectric MLCCs. The stabilization of the secondary output voltage ULoad at constant load is experimentally evaluated for an inductive coupling factor k between 10 % and 30 % for three nonlinear MLCCs #1, #2 and #3. With our proposed passive control strategy ULoad is maintained at -1.2 % and +0.6 % around a median value of 17.3 V (17.1 - 17.4 V) for k ∈ [20 %, 30 %] using MLCC #1, ±0.9 % around a median value of 11.2 V (11.1 - 11.3 V) for k ∈ [10 %, 18 %] using MLCC #2, and -1.6% and +2.6 % around a median value of 5.03 V (4.95 - 5.16 V) for k ∈ [16 %, 30 %] using MLCC #3. The proposed control principle is particularly advantageous for highly miniaturized microimplants, as it allows IPT control without additional semiconductors, sensors and vulnerable communication channels.

A Soft-Switched Three-Phase Inductor Coupling Quasi-Z-Source Integrated Charger With Reduced Output Current Ripple for Electric Vehicles

A Soft-Switched Three-Phase Inductor Coupling Quasi-Z-Source Integrated Charger With Reduced Output Current Ripple for Electric Vehicles

Stimulus responsive wireless sensor integrated smart urine bag for early detection of catheter-associated infections

Urinary catheterization is a routine intervention in intensive care unit (ICU) patients with prolonged immobility. However, extended use of urinary catheters significantly increases the risk of urinary tract infections (UTIs), posing serious healthcare concerns. Early detection of UTIs can effectively prevent disease progression and mitigate additional health complications. Most conventional diagnostic methods rely on periodic urine sample collection and laboratory analysis, which are time-consuming and lack the capacity for continuous, real-time assessment. To address these limitations, we developed a Smart Urinary Bag (SUB) system with an integrated sensor platform designed for real-time monitoring of UTI-associated biomarkers in urine directly within the urinary bag. The sensor platform incorporates two interdigitated electrode (IDE) patterns coated with stimuli-responsive polymers to selectively detect elevations in pH and xanthine oxidase (XOD) levels—two critical biomarkers for urinary infections. These IDEs connect to spiral planar coils, forming sensor tags that enable battery-free, wireless monitoring of urine conditions through near-field inductive coupling with an external reader. The sensor tags, measuring 10 cm × 6 cm, and the coating thickness were optimized using High-Frequency Structure Simulator (HFSS) software to ensure effective wireless readability and sensitivity for practical miniaturization and integration into standard urinary bags. Systematic characterization of the functional coatings confirmed effective compositions that allowed reliable wireless detection of elevated pH (>8) and XOD (>500 U/L) levels in urine, with a response time of less than 3 hours. The sensors maintained stable performance over 14 days under physiologically relevant conditions with high specificity, as verified through tests with both artificial and real urine. As proof of concept, the fully integrated SUB system was tested under simulated patient conditions with varying pH and XOD levels. The platform successfully identified high-risk UTI conditions, enabling timely alerts to healthcare providers for immediate intervention. This platform aims to enhance patient monitoring in ICUs by reducing healthcare provider burden, facilitating early identification of UTI risks, and promoting timely interventions, ultimately reducing antibiotic overuse and addressing the challenge of rising antibiotic-resistant bacterial strains.

Design of an Accurate, Planar, Resonant Microwave Sensor for Testing a Wide Range of Liquid Samples

In this paper, an inductively coupled capacitively loaded ring resonator (IC-CLRR)-based microwave resonant sensor has been proposed for the accurate identification of any unknown liquid sample and its permittivity estimation. The key element of this work is the sensor’s wide range capability towards the non-invasive testing of liquids covering a wide dielectric range of liquid samples, i.e., εr = 2 to 80. The proposed microwave sensor is etched over the FR-4 substrate and is excited by the microstrip line through inductive coupling. The placement of an unknown liquid sample in close proximity to the sensor alters its natural resonant frequency due to a change in effective inductance and capacitance as per the dielectric property of the liquid sample. Further, a mathematical formulation using curve fitting has also been derived. The measurement results show a good accuracy in estimating the permittivity and, thus, the unknown liquid identification capability of the designed sensor with a very low error (nearly 5%). This sensor design is simple to fabricate, cost-friendly, and small in size.

LC dynamic signal modeling and analysis of resonant frequency measurement error under rapid eye movements interference

Abstract LC resonant wireless passive intraocular pressure (IOP) sensors measure IOPs by mapping them to LC resonance frequencies. However, during the sweeping acquisition process of each LC signal frame, possible rapid eye movement (REM) can interfere with the wireless mutual inductance coupling, leading to the signal distortion and resulting in the error of resonance frequency measuring. Currently, there is a lack of modelling analysis of the errors generated by REM effect, resulting in an absence of guidance for reducing the impact. Therefore, here, we start from the perspective of the signal model and establish the LC dynamic signal model for sweeping acquisition. By means of the limit state analysis and Monte Carlo simulation, we analyze the influence of external REM parameters (including REM range and velocity) and internal parameters of the LC sensing system (including the quality coefficient of LC sensor, diameter, and number of turns of the reader coil, signal sweep acquisition speed and period) on the errors. We demonstrated theoretical relationship between the extreme errors with these parameters and verify it through a computer simulation. Based on the results, we propose to optimize the internal parameters of the LC sensing system to reduce the REMs effect on errors, safeguarding the quality of signal acquisition and improving the measurement accuracy.

Float solenoid balun for MRI.

Baluns are crucial in MRI RF coils, essential for minimizing common-mode currents, maintaining signal-to-noise ratio, and ensuring patient safety. This paper introduces the innovative float solenoid balun, based on the renowned solenoid cable trap, and conducts a comparative analysis with the widely used float bazooka balun. Leveraging robust inductive coupling between the cable shield and float resonator, the float solenoid balun offers compact dimensions and post-installation adjustability. Through electromagnetic simulations and bench testing across static fields (1.5, 3, and 7T), the float solenoid balun demonstrates superior common-mode rejection ratios compared to the float bazooka balun. Notably, its float design facilitates easy post-installation adjustment and eliminates the need for soldering on the cable shield, enhancing usability and reducing risks. Furthermore, the solenoid balun's compact footprint addresses the increasing demand for smaller baluns in modern MRI scanners with denser coil arrays. The float solenoid balun offers a promising solution by conserving valuable space within the RF coil, simplifying practical hardware implementation and cable routing, and accommodating more elements in RF arrays, with great potential for enhancing MRI performance.

Towards atomic-scale smooth surface manufacturing of β-Ga2O3 via highly efficient atmospheric plasma etching

Abstract The highly efficient manufacturing of atomic-scale smooth β-Ga2O3 surface is fairly challenging because β-Ga2O3 is a typical difficult-to-machine material. In this study, a novel plasma dry etching method named plasma-based atom-selective etching (PASE) is proposed to achieve the highly efficient, atomic-scale, and damage-free polishing of β-Ga2O3. The plasma is excited through the inductive coupling principle and carbon tetrafluoride is utilized as the main reaction gas to etch β-Ga2O3. The core of PASE polishing of β-Ga2O3 is the remarkable lateral etching effect, which is ensured by both the intrinsic property of the surface and the extrinsic temperature condition. As revealed by density functional theory-based calculations, the intrinsic difference in the etching energy barrier of atoms at the step edge (2.36 eV) and in the terrace plane (4.37 eV) determines their difference in the etching rate, and their etching rate difference can be greatly enlarged by increasing the extrinsic temperature. The polishing of β-Ga2O3 based on the lateral etching effect is further verified in the etching experiments. The Sa roughness of β-Ga2O3 (001) substrate is decreased from 14.8 to 0.057 nm within 120 s, and the corresponding material removal rate reaches up to 20.96 μm/min. The polished β-Ga2O3 displays significantly improved crystalline quality and photoluminescence intensity, and the polishing effect of PASE is independent of the crystal faces of β-Ga2O3. In addition, the competition between chemical etching and physical reconstruction, which is determined by temperature and greatly affects the surface state of β-Ga2O3, is deeply studied for the first time. These findings not only demonstrate the high-efficiency and high-quality polishing of β-Ga2O3 via atmospheric plasma etching but also hold significant implications for guiding future plasma-based surface manufacturing of β-Ga2O3.

Fully Wireless, In Vivo Assessment of Superimposed Physiological Vital Signs Using a Biodegradable Passive Tag Interrogated with a Wearable Reader Patch

AbstractState‐of‐the‐art biosignal monitoring systems strive to achieve a balance between biocompatibility, biodegradability, and miniaturized, unobtrusive signal acquisition, thus requiring further research for improved user safety, mobility, and comfort. Here, a fully wireless sensing system is presented for real‐time in vivo assessment of physiological vital signs, addressing these challenges to enhance performance and user experience. The system features a biodegradable passive tag with a nanoscale crack‐based strain gauge sensor connected to a coil antenna on a gelatin‐ionic liquid substrate (GIS). The thermal crosslinking in the GIS promotes adhesion, while the presence of ionic liquid decreases the self‐resonance frequency of the BCA to below 100 MHz, enabling the device to operate in detuned mode. A lightweight (1.547 g) wearable reader patch interrogates an implanted passive tag via near‐field inductive coupling and transmits sensory data to peripheral devices via Bluetooth. Thus, the system ensures minimal tissue absorption and extended transmission range while consuming ≈80 mW of power during operation. In vitro and in vivo studies, culminating in successful implementation within a rat model, validated the implanted tag's biocompatibility and the system's capability to wirelessly acquire and process superimposed physiological vital signs, highlighting its potential to enhance patient outcomes through improved diagnostic and monitoring practices.

GaN-Based Interleaved Four-level Flying Capacitor Triangular Conduction Mode (TCM) Converter with Coupled Inductors

GaN-Based Interleaved Four-level Flying Capacitor Triangular Conduction Mode (TCM) Converter with Coupled Inductors

A small variable rate underwater CAN-fiber data transmission system

Abstract Currently, the primary data transmission methods underwater include optical fibers, radio waves, blue-green light, underwater acoustics, electric fields, and inductive coupling electric fields. Optical fibers are extensively utilized for underwater data transmission due to their benefits, such as long transmission distances, strong anti-interference capabilities, good environmental adaptability, and minimal limitations from navigating carriers. However, optical fibers face challenges in meeting high-speed transmission requirements beyond 10km due to communication distance constraints. As a result, optical fibers are often used as a replacement for the CAN communication system, but they come with drawbacks such as large volume and fixed speed. They lack dynamic testing and release-length experiments, supporting only one-time use. To tackle these issues, this paper presents a comprehensive design of a variable (adaptive) baud rate optoelectronic data transmission system for underwater applications with limited space. Lake trials were conducted under various conditions, demonstrating the system’s excellent performance. It ensures high-speed data transmission without interference and extends communication distances. This system holds significant reference value for the engineering implementation of composite data transmission systems constrained by space.

Dual-tuned floating solenoid balun for multi-nuclear MRI and MRS

Common-mode currents can degrade the RF coil performance and introduce potential safety hazards in MRI. Baluns are the standard method to suppress these undesired common-mode currents. Specifically, floating baluns are preferred in many applications because they are removable, allow post-installation adjustment and avoid direct soldering on the cable. However, floating baluns are typically bulky to achieve excellent common-mode suppression, taking up valuable space in the MRI bore. This is particularly severe for multi-nuclear MRI/MRS applications, as two RF systems exist. In this work, we present a novel dual-tuned floating balun that is fully removable, does not require any physical connection to the coaxial cable, and has a significantly reduced footprint. The floating design employs an inductive coupling between the cable solenoid and a floating solenoid resonator rather than a direct physical connection. Unlike the previous floating solenoid balun, this balun employs a two-layer design further to improve the mutual coupling between the two solenoids. A pole-insertion method is used to suppress common-mode currents at two user-selectable frequencies simultaneously. Bench testing of the fabricated device at 7 T demonstrated high common-mode rejection ratios at Larmor frequencies of both 1H and 23Na, even with a compact dimension (diameter 18 mm and length 12 mm). This balun's removable, compact, and multi-resonant nature enables light-weighting, allows more coil elements, and improves cable management for advanced multi-nuclear MRI/MRS systems.

An application of multi-magnetic circular planar spiral relay to improve the performance of wireless power transfer system

Introduction. The system of delivering electricity without wires is known as wireless power transfer (WPT). The WPT system has been extensively used in a number of industries, health, telecommunications, and transportation. However, the distance between the transmitter and receiver coils has a significant impact on its efficiency. Lower power can be generated between coils the farther apart they are, and vice versa. The novelty of the proposed work is innovative in that it develops a multi-magnetic circular planar spiral relay to improve the WPT system’s performance and designs circular planar spiral coils to achieve an appropriate inductance value for the 5 kHz matching frequency. The goal of paper is to create a circular planar spiral coil with an appropriate inductance value for the 5 kHz matching frequency. Methods. The transmitter circuit, receiver circuit, and DC voltage source are parts of the WPT system. The inverter circuit uses the inductive coupling technique to transform the DC power source into AC voltage on the transmitter coil. The suggested coil is additionally employed as a multi-magnetic circular planar spiral relay in order to increase the mutual inductance between the receiver and transmitter coils. Results. To monitor the power improvement that results from adding a multi-magnetic relay to the system, the transmitter coil, receiver coil, and multi-magnetic relay are positioned at specific distances from each other. With Vdc = 30 V and dtr = 21 cm, the power received at the receiver coil can therefore be improved by up to 67 %. Practical value. The multi-magnetic circular planar spiral relay applied in the WPT system has been investigated in an experimental study and it can be applied for DC load. References 26, table 1, figure 18.

Performance of a Radio-Frequency Two-Photon Atomic Magnetometer in Different Magnetic Induction Measurement Geometries.

Measurements monitoring the inductive coupling between oscillating radio-frequency magnetic fields and objects of interest create versatile platforms for non-destructive testing. The benefits of ultra-low-frequency measurements, i.e., below 3 kHz, are sometimes outweighed by the fundamental and technical difficulties related to operating pick-up coils or other field sensors in this frequency range. Inductive measurements with the detection based on a two-photon interaction in rf atomic magnetometers address some of these issues as the sensor gains an uplift in its operational frequency. The developments reported here integrate the fundamental and applied aspects of the two-photon process in magnetic induction measurements. In this paper, all the spectral components of the two-photon process are identified, which result from the non-linear interactions between the rf fields and atoms. For the first time, a method for the retrieval of the two-photon phase information, which is critical for inductive measurements, is also demonstrated. Furthermore, a self-compensation configuration is introduced, whereby high-contrast measurements of defects can be obtained due to its insensitivity to the primary field, including using simplified instrumentation for this configuration by producing two rf fields with a single rf coil.

Summary of Wireless Charging Technology for Electric Vehicles

The rapid popularity of electric vehicles has promoted the rapid development of wireless charging technology. This paper reviews the current research progress and application status of wireless charging technology for electric vehicles. Inductive coupling, magnetic resonance coupling and non-directional radiofrequency radiation, three main wireless power transmission methods, including their principles and advantages, are introduced. In addition, the practical application of the technique, such as near field application and far field application, is also discussed. Finally, the development direction of wireless charging technology for electric vehicles in the future is looked forward, including the key technical paths of optimizing system design, improving energy transmission efficiency and reducing system cost. In summary, this paper aims to provide comprehensive theoretical support and practical guidance for the research and practice of wireless charging technology for electric vehicles.

Monolithic ceramic waveguide filter using a transition between GCPW feed and ceramic waveguide for 28 GHz

AbstractIn this letter, a mm‐wave monolithic ceramic waveguide filter using a transition between a grounded coplanar waveguide (GCPW) feed and a ceramic waveguide has been proposed. The published studies on monolithic ceramic waveguide filters with wideband properties for the mm‐wave are lacking. A desired external quality factor, satisfying wide bandwidth, is achieved using both inductive and capacitive couplings in the transition. The inductive coupling is realized with a waveguide's hole directly connected to the microstrip line probe of the GCPW. The capacitive coupling is employed with the slots of both GCPW and ceramic waveguide, which are placed facing each other. Adopting the presented transition, the inline monolithic ceramic waveguide filter for a fourth‐order Chebyshev response was designed. The fabricated filter provided the insertion and return losses of lower than 1.2 dB and higher than 10 dB, respectively, at frequencies from 26.43 to 29.76 GHz, with a fractional bandwidth of 11.85%.